Systems for the open-loop and closed-loop control, respectively, of the driving dynamics of automobiles are known. The control of the braking system is the priority here. In such systems, the most precise information possible about the vehicle mass is of major significance.
If the motor vehicle is a commercial vehicle having a towing vehicle and a trailer/semi-trailer, an optimal coordination of the braking forces with regard to economic efficiency, safety and driving comfort can be attained if the masses of the towing vehicle and the trailer/semi-trailer are known as accurately as possible. If the mass of the entire truck with trailer is known, then, given the known mass of the towing vehicle, the mass of the trailer/semi-trailer can be determined. Since, however, according to its intended purpose, large differences can occur in the payload of commercial vehicles and thus in the total mass of the vehicle, the total mass and the distribution of the mass between the towing vehicle and the trailer/semi-trailer must continually be redetermined. Thus, the driving stability can be increased by suitably distributing the braking torque on the individual wheel brakes.
German Patent Application No. 42 28 413 describes a determination of the total mass of a vehicle, in which the longitudinal acceleration of the vehicle and the appertaining driving and propulsive forces are measured at two different points of time in brief succession during an acceleration process of the vehicle. The vehicle mass can then be determined as a function of these measured variables. It is assumed here that the driving resistance while determining the mass does not change significantly, for example due to a change in the roadway slope.
An object of the present invention is to determine mass as simply as possible and with greatest possible precision in view of a possibly sloped roadway.